1. Field of the Invention
The present invention relates to a sheet-shaped secondary battery of layer built type using polymers such as a polyacetylene as the electrodes.
2. Prior Arts
Recently, batteries using polymers having conjugated double bonds such as a polyacetylene as the electrodes are drawing attention, since they have high energy densities, and thus can be used as one of the starting materials for making batteries of small size and light weight. Such a battery is described, for example, in Japanese Patent Application Kokai (Laid-open) No. 56-136469/1981.
The present inventors have made extensive studies for developing a sheet-shaped battery which is flexible and usable even when flexed and has excellent durability as a secondary battery. As a result of the studies, it was found that the polymers having conjugated double bonds such as a polyacetylene have excellent flexing resistance and can preferably be used in sheet-shaped secondary batteries. It was also found out from the studies by the present inventors that, when a plurality of unit cells, each of which uses said polymers, is laminated to form a layer built type battery, even if either one of two electrodes is provised with a thin metal layer, this battery functions fundamentally as such, but does not exhibit with a sufficient charging-discharging characteristic and this is due to that current-collecting action is not properly done in the battery.